BT-80 based Saturn V/ "Saturn I-F"

[NJRick]

Luke,
what a fascinating post....quick question for you....one of the limitations with the Saturn 1b (my all time fav rocket...) was its inability to lift a fully fueled CSM . I believe the only payload that an Apollo equipped 1b ever carried was the docking adaptor on ASTP. with those limitations, do you think that a single F-1a would have still been the option NASA would have chosen? Seems like could have had the same payload limitations as the 1b?

Rick

 

[luke strawwalker]

Luke,
what a fascinating post....quick question for you....one of the limitations with the Saturn 1b (my all time fav rocket...) was its inability to lift a fully fueled CSM . I believe the only payload that an Apollo equipped 1b ever carried was the docking adaptor on ASTP. with those limitations, do you think that a single F-1a would have still been the option NASA would have chosen? Seems like could have had the same payload limitations as the 1b?

Rick

Hey Rick...

Actually Mike Robel (who's done some REALLY cool alternative Saturn models (static) and I were discussing just this issue over on YORF. He pointed out much the same thing you just did-- that while the 3 million pound thrust of a pair of F-1's APPEARS at first blush to be "too much" for a Saturn IB replacement vehicle, in actuality it is not, and for the very reasons you pointed out. The Saturn IB's payload limitations basically doomed it. For any type of mission with the Apollo CSM beyond LEO but still in Earth's vacinity (say to geosynchronous Earth orbit or the Lagrange points closer to the moon such as L1 or L2, a fully-fueled capability on the CSM was absolutely required. Being able to launch a substantial payload with the Saturn IB replacement would also have been highly valuable, especially if you decided to do an Earth-orbiting space station project and resupplying that station periodically, unlike Skylab which basically launched "fully stocked" and used the LOX tank of the converted S-IVB stage "workshop" for a "septic tank". A continuously manned, periodically resupplied space station in LEO by the US would have required some sort of resupply/disposal capability, just as the Soviets learned with their Salyut stations when they developed the robotic Progress freighters for exactly that function. If you developed something akin to say the ATV/HTV, or even a much simpler and cheaper "MPLM" type "pressurized tuna can" that could be loaded with supplies, water, boost propellant, etc. that was carried up under the SLA panels on the top of the Saturn IB replacement's S-IVB stage to orbit, and then have it extracted by a transposition and docking manuever identically to how the CSM docked and extracted the LM from the spent stage, and then transported that module to the space station and docked it to the station, or even simply delivered it into station keeping with a space station where it could be grappled by a robot arm and berthed to the station, leaving the capsule free to dock with the station independently of the resupply module, that module could then be unloaded at will and filled with refuse from the station, and jettisoned for reentry, either from it's own thruster system like Progress, or docked to by the CSM and then dropped back into the atmosphere by a partial de-orbit burn by the CSM followed by undocking and then a prograde burn so the Apollo could reenter later, well away from the disposed of resupply module.

In addition, there were plans for small "conical shaped" space stations that would basically fit in the location of the SLA adapter panels of the Saturn IB. Such a design would be an excellent starting point for space station modules which could have been delivered by a Saturn IB to orbit and brought to the space station for assembly by the CSM, then released and grappled by a robot arm which would permanently dock it to the station at a node connector, much as was done with shuttle and ISS. This is most likely how any successor stations will be constructed in the future now that shuttle is retired (or free-flying modules with propulsion systems sufficient to rendezvous and dock with the other modules forming the station, done either by remote control or autonomously as the Mir modules and Progress freighters did/do... this allows for larger modules to be launched unmanned, and this paradigm certainly would have worked for a Saturn IB successor just as well as it would for Proton and the modern EELV's and/or Ariane V, but OTOH it's AWFULLY convenient to launch a manned spacecraft with the module, like shuttle did carrying most of the ISS modules to orbit.

To be able to do it though, you need a "high thrust" first stage capable of getting that much weight off the ground and up and moving. With a fully fueled CSM and a substantial payload module under the SLA panels, the twin F-1 vehicle would have been ideal. Now, as the fuel is expended and the stage nears fuel depletion and burnout, the 2 million pound + thrust is going to be too much, and start building gees quickly. It would be necessary to shut down one of the F-1's early, since the F-1 couldn't be deeply throttled, and that would complicate things a bit. The off-center thrust shouldn't be too much of an issue... after all shuttles flew for 30 years with EXTREMELY off center thrust from the SSME's on the orbiter with the heavy nearly-half-full ET hanging off the side of the orbiter. This might have been a bit "radical" at the time though... roll control might be something of an issue with one F-1 shut down, but owing to the off-center thrust I think it would still be controllable. The remaining F-1 would have had to 'slew' somewhat to thrust through the center of gravity once the other F-1 was shut down, so the vehicle would be flying "slightly sideways" (much as shuttle did) until the first stage burned out.

In thinking about it, the single F-1 teamed up with a pair of H-1's presents some interesting possibilities. I wish I had access to the tools and knowledge to be able to analyze the possibilities properly, but a thought exercise is still possible. Obviously the addition of another 400,000 lbs thrust in addition to the 1.5 million pounds thrust of the standard F-1 would give you just under 2 million pounds thrust, a pretty decent 'bump up' from the standard Saturn IB. Now as the stage gets lighter from propellant burning, acceleration increases (gees) and at some point you're going to have to either deeply throttle or shut something down to reduce thrust. Saturn IB did this by shutting off the center four engines and running on the outer four for 20-30 seconds or so (IIRC, but not exactly) before stage burnout. You have two choices on this particular stage-- shut down the twin H-1's, or shut down the F-1. Shutting down the twin H-1's leaves you without roll control, but this might not be critical. But it also wouldn't drop but about 400,000 pounds of thrust or so-- the F-1 would still be churning out 1.5 million pounds thrust, which is about what the Saturn IB started off with. This would probably throw too many gees on the payload/structures. The other possibility, shutting down the F-1, means you can now burn your twin H-1's quite a bit longer, since they burn propellant FAR slower than the hungry F-1 does. It drops your thrust to about 400,000 pounds, or roughly the equivalent of a PAIR of J-2S's. This makes for some interesting performance. You're still carrying the weight of the probably 80% empty first stage propellant tanks, and you're dragging along tons of dead weight of the F-1, but you're going to burn the first stage quite a while longer on just the pair of H-1's than you would otherwise. The thrust is somewhat low, but it shouldn't be underthrusted to the point gravity losses become objectionable. Essentially the first stage would then be acting somewhat like a twin-J-2S "second stage", only powered by kerosene burning H-1's and using the first stage tankage, and dragging along the dead F-1 (I don't think for a moment it'd be worth it to design a separation system into the stage to drop the F-1 after shutdown). Once the twin H-1's have burned to propellant depletion, the first stage is jettisoned and the single J-2S upper stage takes over to deliver the CSM/cargo to orbit.

Later! OL JR

 

[NJRick]

Luke,
the F-1 and H-1 combo is interesting....perhaps they could have dropped the H-1's.....I am thinking something like the Atlas used to do...didn't the Atlas drop the outboard engines? ...staging I guess...but I thought they dropped off and the bird continued on with the central sustainer engine.

Rick

ps- hey Luke...your Titan MOL build thread inspired me...I just bought the Titan3 from Dr. Zooch!

 

[luke strawwalker]

Luke,
the F-1 and H-1 combo is interesting....perhaps they could have dropped the H-1's.....I am thinking something like the Atlas used to do...didn't the Atlas drop the outboard engines? ...staging I guess...but I thought they dropped off and the bird continued on with the central sustainer engine.

Rick

ps- hey Luke...your Titan MOL build thread inspired me...I just bought the Titan3 from Dr. Zooch!

Thank you... glad you liked the Titan III MOL... it's a neat kit, I think you'll like it!

Yes, Atlas dropped the outer two booster engines and the outer ring of the thrust structure. The outer two engines shut down, the propellant lines separated, and the connections/wiring severed, and then the entire outer ring and booster engines jettisoned, sliding aft on 'rails' that guided it past the still thrusting center engine. In a lot of ways, Atlas was REALLY well ahead of its time.

Personally I think that if you had a hypothetical Saturn IB with a central F-1 flanked by a pair of H-1's, you'd do better to shut down the F-1 early and jettison it instead of the H-1's for reasons already mentioned. It'd also be quite a bit simpler and easier to do. Of course such a hypothetical vehicle, which was proposed incidentally (using both a single F-1 engine and some combination of H-1 engines) probably would have never happened due to the ever-present funding issue and having some of the downsides of both the F-1 version AND the all H-1 version...

Later! OL JR

PS. Check out my Zooch Atlas Agena build thread-- I think you'll like it!

 

[NJRick]

Luke,
your Atlas agena thread is already book marked over here for future reference!! one of these days, I am going to build the doc's Mercury Atlas...just another cool rocket...man does Dr. Zooch have some really neat rockets....I mean....its tough to pick one to build....also found a good build thread by hcmbanjo on the Titan....in reading the threads, how do you make such fine cuts with the wraps to make the small bands on the SRB's? they really make the SRB's pop if you ask me...but to date, I haven't been too good with my fine cutting....I think I saw you reference a balso stripping tool...I had no idea what that was and sure enough...found one on e bay for less than $10....I should be getting that in a day or so...I think that will help with my small balsa cuts....this forum is just a wealth of info for guys like me who are coming back to the hobby....stuff out there that I never heard of before. I am trying to improve with each build.....trying to get the balsa nose cones to look like yours.....I mean yours look like plastic...I built the 1b and it is neat....but I had no idea how to fill them so I didn't....I went to the Zooch Soyuz and after reading some of the build threads by guys like you, foose hcmbanjo and others....... started working with wood filler....made a big improvement, but still a ways to go in perfecting my sanding techniques...I am trying to get better with each build.....again, thanks for your build threads!


Rick

ps- my basset hound loves your basselope defense system! not much of a guard dog up here, kinda a cross between a beagle and a rug....she sleeps 22 hours a day....but we love her! just an great dog. friendly as can be to anybody or anything that comes to the door.

 

[luke strawwalker]

Luke,
in reading the threads, how do you make such fine cuts with the wraps to make the small bands on the SRB's? they really make the SRB's pop if you ask me...but to date, I haven't been too good with my fine cutting....I think I saw you reference a balso stripping tool...I had no idea what that was and sure enough...found one on e bay for less than $10....I should be getting that in a day or so...I think that will help with my small balsa cuts....this forum is just a wealth of info for guys like me who are coming back to the hobby....stuff out there that I never heard of before..

For the SRB bands, I just use a metal straightedge (a stainless steel ruler I bought at Walmart) and a hobby knife. Slide the ruler up to about 1/16 or so wide strip, make sure it's perfectly parallel, and cut along the edge with the hobby knife (sharp #11 X-Acto blade). Make three cuts to cut through the cardstock cleanly. I pile up about 30 of these small stripes of each (black and white). Put down a piece of wax paper, smear a thin layer of white glue on the back of each (edge to edge) and end to end and then CAREFULLY roll them onto the rocket. Align the end with the edge of the wrap (so it's hidden behind the SRB when done in the bottom of the glue joint) and, pinning it down with one finger, gently roll the SRB, keeping it gently taut and rolling it onto the SRB wrap as you turn the SRB in your hand. It takes a bit of practice, but once you get the hang of it, it's not bad.

I bought a balsa stripper but found it's not much use for this sort of thing... it works well with balsa that's thicker, but for cardstock it doesn't have the kind of control you need to do a good job cutting a perfectly even 1/16 inch wide or so strip.

I am trying to improve with each build.....trying to get the balsa nose cones to look like yours.....I mean yours look like plastic...I built the 1b and it is neat....but I had no idea how to fill them so I didn't....I went to the Zooch Soyuz and after reading some of the build threads by guys like you, foose hcmbanjo and others....... started working with wood filler....made a big improvement, but still a ways to go in perfecting my sanding techniques...I am trying to get better with each build.....again, thanks for your build threads!.

I harden the cones using ultra-thin CA from Hobby Lobby (pink bottle, available cheap with the 40% off coupon if you watch the HL website). Do this outside with the wind blowing from your SIDE because the CA makes some potent fumes and even gets hot as it soaks into the balsa, but it turns it into a composite material and considerably strengthens the balsa cones/transitions. Try to keep it off the shoulders of the transitions and cones though-- it increases the diameter slightly and makes the balsa "much rougher" feeling. Once the CA has hardened, sand the cones/transitions down with 220 grit paper until they're smooth again (probably 5-10 minutes per cone I'd guess) and once you're satisfied, you can paint on some Elmer's Carpenter's Wood Filler thinned to about the consistency of squeeze bottle hot dog mustard. Paint it on with a paintbrush and let it dry a couple hours. Sand it down with 220 grit until it's smooth as you want. Always sand in circles, never in a straight line (unless you're removing excess filler that happened to get below the shoulder of the cone/transition). Also, ALWAYS keep the part turning slowly in your hand as you sand to avoid flat spots.

Once you've got it sanded down smooth, it's time to primer. I like the Walmart Colorplace 99 cent a can primer, the red has a bit more solids than the gray, but both work well... unfortunately they're BOTH getting nearly impossible to find. SO, I've switched to Rustoleum. We'll see how that works... Put a couple or three coats of primer on the cones (I've found that taping them down to a cardboard "handle" and masking off the shoulder of the cone/ transition is extremely helpful). Once they're primed and dried for several hours/overnight, sand again with 220 grit until they're really smooth. Switch to 440 grit sandpaper and sand them again, wiping them off periodically with a damp paper towel, and hold it up to a light so the light "glints" off the part, or down the length of the cone. Turn it slowly and look for "irregularities" in the reflected light. If the glint "breaks" or gets wavy, you know you have uneveness that you need to sand out a bit more. You can use a bowl of water to dampen the sandpaper, daub it on a towel to remove the excess water, and "damp sand" the cones to get them literally "mirror smooth". A little bit of moisture on the cone/transition is ok-- the sanding dust will form 'mud' as you sand from the moisture. Wipe this off periodically with a damp paper towel. The main thing is, don't sand using a lot of pressure-- let the paper do the work. Sand in small circular motion, never in straight lines if you can possibly help it, and keep rotating the part slowly in your hands as you're sanding to avoid flat spots or sand-thru's...

When you're satisfied with the finish, they're now ready for paint, once thoroughly dry. Walmart Colorplace Flat White and Flat Black is EXCELLENT for "ant-scale" rockets like these...

Rick

ps- my basset hound loves your basselope defense system! not much of a guard dog up here, kinda a cross between a beagle and a rug....she sleeps 22 hours a day....but we love her! just an great dog. friendly as can be to anybody or anything that comes to the door.

hehehe... That's good... We're up to our butts in cats around here... LOL

That's from an old "Bloom County" cartoon I saw when I was in high school and photocopied when I worked in the library there...

later! OL JR

PS. Keep watching this thread, as I CA hardened the cones and SLA transitions for these builds before I got sick last week or so ago, but I haven't had a chance to get them sanded yet... Keira got sick, car broke down on my wife after school one day, A/C quit in the house, calves have been breaking out to eat ditch bottom grass, and all this on top of the usual tap-n-tango show... LOL

I'll be detailing the sanding, filling, priming, and painting of the cones fairly soon (when I can get back to work on the builds!)

 

[NJRick]

Luke...THANK YOU!!!! great tips for a newbie!!

 

[luke strawwalker]

Ok... FINALLY getting back to work on the Saturn V...

After drawing all the detail locations on the main stage tubes using the wraps I previously made, now I turn my attentions to the nosecones and transitions that represent the Apollo capsules and SLA panel assemblies.

I'd already hardened them with ultra-thin pink bottle CA from Hobby Lobby a couple weeks or so ago. So, I took the 220 grit to them and sanded them down smooth. This eliminates the "grit" that the CA raises (balsa hairs and hardened dust) and gets them smooth enough for filler.

Now's the time to mask off the cone shoulders-- makes things a lot easier later on...

This time I tried something new-- ultra-lightweight spackle from Ace Hardware. I've used it before filling gaps on my nephew's 4H rockets (well, showing him how to do it) and it worked ok. I tried a new method this time. I wet a small paintbrush by dipping it in a bowl of water, knocking off the excess water, and brushing the top of the spackle to moisten it and mix in the water, and transferring it onto the brush. Then I brushed the thinned spackle onto the cones. I noticed that it doesn't go on quite as nice as the thinned Elmer's Carpenter's Wood Filler that I usually use, but it went on "ok"... sorta like cake icing... then I set them aside to dry.

Next I hit them with 220 grit sandpaper again to take the filler down to the level of the wood. It sands pretty good, but not as well as thinned CWF (carpenter's wood filler). Once I had the cones sanded down, I taped them to cardboard "handles" for priming...

Moved out onto the porch and gave them a couple or three good coats of primer. Now they're drying...

Later! OL JR

 

[luke strawwalker]

With the cones primered and drying, I'm shifting gears to start some detailing...

First off is the S-II stage liquid hydrogen line fairings. There were five of these, four of which are evenly spaced between positions I, II, III, and IIII, with the fifth slightly off-center in Position II. The line fairings are right at 24 inches in diameter on the real vehicle. I bought two packages of different size bamboo skewers awhile back. The larger ones are about 0.156 in diameter, which at 1/152 scale, is just about 24 scale inches in diameter... PERFECT!

SO, referring to my handy NARTS Saturn V blueprints, I scaled out the size of the fairings, since they taper to an off-center cone on each end. They're actually a rather complex shape, as they actually have another "mini-fairing" on the left hand side of the individual fairings, but I'm going to just make them cylindrical and call it good. First we have to sand the bamboo skewer down smooth, as they are quite rough from the package.

Next, we need a 'reference line' the length of the skewer. I put two rulers on top of each other and traced the line onto the skewer, sorta like a miniature "door jamb" method. This is so we can get BOTH the off-center points in the same "plane" on the fairing. The pencil line isn't particularly durable on the bamboo, so I traced over it with Sharpie marker...


Next, I drew a scale representation of the fairing lengths on the edge of one of my worksheets... the fwd. tapered end is 0.461 inches at 1:152 scale, the center 'cylindrical' section is 1.033 inches, and the aft taper is 0.421 inch. Now I can handily transfer the measurements to the bamboo as I build each one...

Rolling it back and forth with the pencil inscribes "guide rings" on the bamboo for the tapers. I quickly learned to go over them with magic marker just to make the marks more durable. Also, put an arrow denoting "fwd" on the thing since the tapers are different lengths.

Next, using the hobby knife, whittle the bamboo down to the desired off-center conical shape. The point of the cone should be on the reference line and flat against the side of the fairing. I tried simply sanding them to shape, but the bamboo is HARD and doesn't sand easily-- whittling reduces about 80% of the work of making the tapered ends...

More to come! OL JR

 

[luke strawwalker]

Next we sand the conical end down smooth. This is most easily done with a piece of 220 grit sandpaper held tightly down on the table, and sanding the pointed end while gently rolling it back and forth, accounting for the off-center point.

Bamboo will sand down to a needle-like point, so periodically round this off a bit to avoid skewering yourself (or the sandpaper). A few passes over/around the tip will take it down nicely. It doesn't take too long to make the tip quite smooth and properly shaped...

Next we'll cut the bamboo to the proper length for the fairing... roll the bamboo a few times with the hobby knife blade to cut the outside grain of the bamboo-- this will make for a cleaner cut. You CAN cut all the way through it by rolling back and forth repeatedly under pressure, but the hardness of the bamboo makes this a LOT of work and takes a long time. We just need to cut the outer grain a bit so the bamboo doesn't 'split' when we cut it.

It goes a LOT faster cutting it with a razor saw, after you've cut through the outer layer a bit to prevent splitting... bamboo is hard and it takes a bit to cut through it.

Once you're finished cutting it off, true the end up a bit on the paper and you're ready to start carving the other end of the fairing...

Later! OL JR

 

[luke strawwalker]

Using the hobby knife, whittle the other end down to the proper contour...


Once you've got the basic shape, we'll refine it by sanding to smooth everything out...

Roll it as you sand it, and be sure you change the angle as you roll it to account for the off-center tip...

Once you're finished sanding, it should be just about perfectly shaped...

Later! OL JR

 

[luke strawwalker]

Once you have the first one, ensure that it's the right size and shape, and trim it to fit the model. I find that the step up where it goes over the corrugated paper leaves an ugly and weak gap under the fairing where it attaches to the tube. So I trimmed and sanded a 'step' into the back part of it to lay flat on both the corrugated paper and the tube.

When you start doing the others, compare them all to the first one and make sure they all match for size, shape, and length.

Transfer the marks from the "step" in the first one to the second and subsequent fairings... that way they all sit the same on the tube fore/aft.

Using a rocking motion with the hobby knife, cut into the fairing a bit to make a clean cut up to the "step".

Shave the fairing underside down on the back part of the fairing, that will sit on top of the corrugated paper. This will allow for the additional thickness of the corrugated paper on the tube.

The hobby knife can only do so much-- the bamboo tends to carve "by the grain" and leave a slightly irregular surface. A few passes with a hobby file will take it down smooth as silk and ensure it's level all the way from the aft tip to the step...

Later! OL JR

 

[luke strawwalker]

Next we need to flatten the front half a little bit, so it sits flat on the tube instead of rocking and rolling when we try to glue it down-- this will make for a stronger joint that will look better, since the fairings are not actually cylindrical but a "rounded box" shape merely to cover the liquid hydrogen lines where they come out of the periphery of the LH2 tank and "go around the outside" of the liquid oxygen tank underneath it, before the lines disappear back into the stage along the thrust structure to the J-2 engines.

A little touch-up sanding ensures a good tight fit. We don't want to sand down anywhere near as much as on the step side, just enough to keep the fairings flat and level when glued on the rocket.

Test fitting ensures a good, gap free joint.

Once all five fairings have been finished, line them up and make sure they're all the same length, as close as possible anyway. Pick three that are as close as possible to each other and use them on Position II, where the three fairings in close proximity to each other will make any differences particularly noticeable. The "oddballs" can go on the other side of the rocket where they're "by their lonesome"...

On photos of the real S-II stage, you can see that there is actually some tapered insulation that sticks up above the surface of the stage, onto which the fairings are mounted. There is also a "ring" of this smooth insulation just above the corrugated aft skirt of the stage, and each fairing also has a smaller block of this tapered insulation on the right side of the fairing (for some sort of mini-fairing/bump). The center fairing on position II also has a pretty good sized block of tapered insulation on the left hand side of it, on the position II centerline, for a LOX or LH2 umbilical or vent connection. I cut printer paper to size with a hobby knife and straightedge and glued it in the proper locations on the stage where the fairings will go. This will give a slight "3-D" effect to show where the tapered insulation actually is on the stage when painted (I hope). It looks a little rough now but it'll look a lot better painted (as will the fairings). (no, they're not curved-- it's the camera's perspective...)

Later! OL JR

 

[luke strawwalker]

LH2 fairings all installed on the S-II... haven't filleted them yet. Probably just a touch of Titebond Moulding and Trim Glue should be all that's needed.

Here's the pics... enjoy!





Next back to finishing the balsa cones/transitions...

later! OL JR

 

[luke strawwalker]

Got the cones primed and sanded... ready for paint. Hopefully tomorrow.

The ultra-light spackle (ULS) was interesting... the jury's still out. It seems to clog the paper more and be harder to sand than thinned Carpenter's Wood Filler (CWF). I spent quite a bit longer sanding it out than I typically do with the CWF, and the results didn't look as good when I was done, IMHO. I put the cones on paint sticks and gave them 2-3 good thick coats of primer, and let them dry about 24 hours or so. The ULS seemed to take longer to dry than the CWF does as well.

They sanded out nicely. I've since reattached them to the paint "handles" and have them ready to go out and get painted. One of the transitions and one of the cones have VERY short shoulders to go into the cones, so they don't bump into the other shoulder of the opposing transition/cone with a regular shoulder when installed in the VERY short (about an inch long) Service Module tube. I had to remove the tape from these short shoulders to sand the cone/transition, so instead of re-taping, I decided to substitute a short piece of leftover BT-50 for the painting phase with the short transition and cone together. The "standard length" shoulder cone/transition I left taped and reattached to their paint stick.

Hope to get them painted tomorrow...

Later! OL JR

 

[NJRick]

Luke...this is really looking good!!

 

[luke strawwalker]

Luke...this is really looking good!!

Thanks... working on the paint. Had a slight problem. It actually came a pretty good thunderstorm here this evening-- 50-60 mph winds or so at times and a LITTLE bit of rain (probably in the 1/4 inch range, haven't checked the guage). That of course shut down the painting because the wind basically kicked up a sandstorm as dry as it's been here...

I was painting near the end of one of the older cans and it started spitting, so I'll probably have to let the paint dry and do a color sanding on some of the parts. I'm using flat white so I'll have to see how it looks once dry.

More later! OL JR

 

[NJRick]

Luke,
can I send some of the rain we have been getting up here in the NorthEast to you??...I live in NJ and its been nuts...feels like rain every day.
Last month we got 7 inches of rain...in one day. (and that was before the hurricane rolled up the coast....) My little town of Yardville is probably about 15 minutes down the road from Washington's Crossing, Pa....named appropriately for where George crossed the Delaware to kick some Hessian butts in Trenton in 1776...I don't think I have ever seen the Delaware so high.

your Saturn V is coming out so nice, I am afraid that you might have recreated the pogo too....its a great thread!!

Rick

 

[luke strawwalker]

Luke,
can I send some of the rain we have been getting up here in the NorthEast to you??...I live in NJ and its been nuts...feels like rain every day.
Last month we got 7 inches of rain...in one day. (and that was before the hurricane rolled up the coast....) My little town of Yardville is probably about 15 minutes down the road from Washington's Crossing, Pa....named appropriately for where George crossed the Delaware to kick some Hessian butts in Trenton in 1776...I don't think I have ever seen the Delaware so high.

your Saturn V is coming out so nice, I am afraid that you might have recreated the pogo too....its a great thread!!

Rick

GEEZ... 7 inches of rain in one day... I vaguely remember stuff like that around here... LOL Heck we haven't had 7 inches of rain here ALL YEAR!!! We're basically up to about 6.5 at the moment!!! (We should be around 30-35 inches by now, and finish the year off with about 44-46)

So YALL are the ones getting all our rain! :dark: Later! OL JR

 

[luke strawwalker]

Got some more work done on the Saturns...

Been thinking about the F-1's for awhile... I know I want them, but the problem was scaling them and figuring out how to do it. Here's what I came up with.

I Yahoo searched "F-1 rocket engine" and came up with the wiki page for it, which had a neat graphic with the engine measurements on it. It only had the total height of the engine from bell to swivel, and the diameter of the bell. SO, then I did a quick-n-dirty scaling job off that printout.

Then I went to the jleslie paper models site and downloaded a copy of the paper model of the F-1 engine. I saved it on my hard drive and printed out a copy of the four build sheets on printer paper, since it was a .pdf and I don't know how to manipulate a .pdf and send it to "Paint" or tweak it with the scanner/printer. Basically all I needed was the pattern anyway. I scanned it in and fiddled with it a bit in paint, but Paint doesn't really have any decent scaling tools, so I reverted to the Dell All-In-One printer/scanner/copier on my computer.

I ensured the printouts were the proper size by comparing the scaling bar with an actual ruler-- it was dead on. SO, I scanned in the sheet of the engine bells (upper and lower halves) and since they were 1/48 scale, and the rockets I'm building are 1/152 scale, I divided it out and calculated they needed to be printed at 31.6% to reduce them from 1/48 scale to 1/152 scale. I set the printer to "copy" mode to enable the scaling feature and then set it to print a copy on regular paper at 32%, since it won't let you enter a decimal. I printed off a test copy.

Then, since it looked SO tiny, I decided to verify that my calculations and stuff were correct, so I took a different tack. I divided the measurements I got from the wiki page printout by the scaling factor (1/152) and came up with the scale measurements needed, then went to an online paper transition pattern tool https://www.delorie.com/rockets/transitions.html and entered the appropriate measurements in the appropriate boxes for a "custom" transition to make the bell nozzle of the F-1. It generated the .pdf pattern for me and I printed it out, and then held the new pattern over the 32% copy of the nozzle bell and held them up in front of the white monitor to act as a light table... PRESTO! They lined up perfectly!

Grabbed three sheets of cardstock and printed 32% copies of the nozzles on each sheet, flipped them end for end, and copied again, putting one at each end of the sheet of cardstock (to save cardstock). Now they're ready to cut out and build.

Using the hobby knife, a VERY steady hand, and near X-ray vision (one of these days I need to spring for a magnifying light!) CAREFULLY cut the nozzle bell pattern out of the sheet, cutting just outside the arcs. I cut a small 'backing glue tab' separate from the nozzle ends which were cut flush, so they form a 'butt' joint instead of an ugly 'overlap' joint.

Next, the paper nozzle is "curled" over a pen-- this pre-curls the paper so the nozzle takes the correct shape of the truncated cone (transition). Since the nozzle is wider at the exit than at the top, you have to gradually "slip" the paper a bit on the nozzle side while "holding back" the rotation of the nozzle on the top end side-- notice how the markings are parallel with the writing on the pen barrel... every set of markings on the bell printout should line up with the pen markings as you precurl the nozzle for it to turn out "straight". The writing on the pen barrel makes this very easy to do, along with the markings on the nozzle printout itself. (Normally I do this with two hands, but I had to hold it in place to take the pic).

Next, a layer of white glue is applied to the glue tab and it's glued inside the nozzle end, with half of it sticking out past the edge. Clamp it up with a hemostat to dry...

More later! OL JR

 

[luke strawwalker]

I set up an "assembly line" cutting out the next nozzle and overlap strip while the previous one was "setting up" in the clamp. Once the next one was cut out, I'd switch back to the first one and remove the hemostat, and apply a bit of glue (NOT MUCH!) to the overlap tab, and then glue the nozzle up... making sure that the cut ends of the nozzle printouts align perfectly and butt up tight against each other, then pressing the joint firmly to set the glue. Then, a quick wipe off of any glue squeezed out of the joint to the outside and apply the hemostat clamp again and set it aside. Precurl the next nozzle while the first one dries.

By the time the third one is cut out, the first one is dry and ready to come out of the hemostat. Once removed, a little finessing of the overlap strip on a pen barrel to gently round it a bit, and working the nozzle between your fingers gently, will make it perfectly round. Here's the finished product.

SO after the "wash, rinse, repeat" of the other five nozzles, here's the finished product-- six F-1 nozzles ready to go, more or less... (4 for the outer 4 engines on the Saturn V, 2 for the pair of F-1's on the Saturn I-F)
I was going to make the upper halves and the turbopump exhaust ducts for them, but when I finished the first one, I test fit it over a BT-20 engine tube (which I plan to use for the outboards of the Saturn V and the pair of engines on the Saturn I-F) and they fit perfectly at the upper end, so I may do the duct work directly over the BT-20 to mate the lower nozzle extensions to the BT-20's and make them look more realistic. But this will do for now...

I may also add sewing thread "hat bands" to the F-1 nozzles to make them more realistic looking (another great method learned from Dr. Zooch)...

Later! OL JR

 

[luke strawwalker]

Ok... a lil more work done today...

I started doing some of the details on the S-IVB stage. I wanted to start with the Auxiliary Propulsion Systems. These were thrusters that mounted on the back end sides of the S-IVB to provide stabilization thrusters for the S-IVB during coasting, after the J-2 engine was shut down. They are essentially clover-leaf shaped in cross-section, about 2 feet wide and a little over 4 feet long, tapered at the front end, blunt at the back. I decided to make them out of harder wood than balsa, so I picked up sheet of basswood at Hobby Lobby yesterday evening.

First I measured everything out and scaled the parts from the drawings. Then I cut some stips of basswood. I found out the parts were actually thicker than the sheet of basswood, so I laminated two strips together to make 'blanks' for carving to shape, gluing the strips together with wood glue and clamping them with clothespins while I did some other stuff around the house.

Once they dried, I sanded the blanks down to the correct thickness, almost-- I left a little extra to account for material worked off the other side in shaping. Basically the blanks were sanded down until about half the thickness of one of the strips glued on the back were sanded off. Then, using a coupler inserted into a short piece of BT-60 to stiffen it up, I wrapped sandpaper around a the piece of tubing to sand the correct curvature into the back of the blanks.

Next, the top half is rounded over into a half-cylinder using 220 grit sandpaper...

Next, using a small square hobby file, file a notch into each side of the half-cylinder lengthwise along the piece... this simulates the lower half of the "cloverleaf" shape quite nicely when we're done... File down into the wood until you've basically got an inverted "T" shape...

Now roll the file over the edges as you continue to file the wood away, to round the inverted "T" over into a well rounded cloverleaf shape.

More later! OL JR

 

[luke strawwalker]

With the rough shape of the APS done, we can now start to get the outline right. The front end is tapered to a near-point, and the back end is flat. Start by whittling down the front end a bit with the hobby knife to get the initial shape...

Next, using sandpaper, true the shape up and get the whittling marks out, and round the tip a bit. Then, using the hobby file, I rounded the blended the front parts to the tip, and the upper rounded part (top of the clover leaf) get sanded over to a mini-point on top of the other two... Here's the finished APS ready to glue on...

I then positioned the APS on the aft skirt corrugated foil paper of the S-IVB stage, and gently traced around it with a hobby knife to score it. Then I gently cut through the outer foil layer of the paper and peeled it away to reveal the paper underneath, to promote adhesion of the wood glue.

Then glue the APS in place. I use the fine tip of bamboo skewer to gently "fillet" around them with a tiny drop of wood glue.

Next up, we have to add the ullage rockets on the S-IVB. There are a pair on the Saturn V, spaced 180 degrees apart just off the centerline of the positions opposite the APS pods... First I scaled the parts from the Saturn V blueprints and cut the blanks out of basswood... Then gently round over the leading edges, sort of like sub-miniature fins. Then sand the end of the "motors" flat, and then sand the trailing edge into a slightly swept configuration. The end product should look like this (note they're sitting in a 1 inch square on the cutting mat).

later! OL JR

 

[luke strawwalker]

Next the ullage rockets are attached to the S-IVB in the proper locations using much the same method as the APS pods... I held them in the proper position and used the hobby knife to mark the front and rear edges of the ullage rockets, and then cut away the foil gently, and glued them on using wood glue, and filleted them a bit using a bamboo skewer tip and a tiny drop of glue. Here's the finished ullage rockets and APS pods on the Saturn V S-IVB...

The "Saturn I-F", on the other had, should be set up identically to the S-IVB on the Saturn IB. There are subtle but visible differences. First off, there are THREE ullage rockets equally spaced around the S-IVB, not two as on the Saturn V. Additionally, the two APS pods are shaped differently on the Saturn IB S-IVB stage-- these are simple half-cylinders unlike the clover-leaf shaped ones on the Saturn V S-IVB stage. I haven't made them yet, but I did make a detail wrap for the Saturn IB S-IVB stage and got the ullage rockets glued into position. The cylindrical interstage on the Saturn IB also uses four separation rockets to push the S-IVB away from the Saturn IB first stage. I opted to go with the later Saturn V versions which eliminated all the ullage rockets off the cylindrical S-IC/S-II interstage after Apollo 14 or 15, IIRC. They had dropped from 8 to 4 rockets before that except Apollo 6, IIRC. I'll do some more checking on the Saturn IB's but I bet I'll have to make them and include them on the Saturn I-F.

I also finished painting the cones and unmasked them... they're pretty much done, except for detailing and the towers of course...

Later! OL JR

 

[luke strawwalker]

Got some more work done on the Saturn V... the S-IVB is now completely detailed. All scale details incorporated in the proper locations...

Here's the overall side view including the SLA balsa transition and BT-50 service module, along with the balsa Command Module nosecone. You can see the main systems tunnel, auxiliary systems tunnel, forward umbilical connect and a flat telemetry antenna...

Here's the other side, showing the APS, LH2 feedline fairing, LH2 chilldown pump fairing, and ullage rocket...

The main and auxiliary systems tunnels, the telemetry antenna in the middle, and the forward umbilical at the very top edge.

The APS, chilldown pump fairing (made from a sanded down to scale toothpick), LH2 fill line fairing (half of a sanded down bamboo skewer), aft umbilical connect plate (cardstock), main systems tunnel, ullage rocket, and LH2 chilldown return line fairing (sanded down toothpick)...

Ullage rocket, LH2 chilldown return line fairing, LH2 fuel line fairing (sanded a bit to proper shape), APS, LH2 chilldown pump fairing...

Later! OL JR

 

[luke strawwalker]

Started working on the Saturn I-F S-IVB stage detailing... Being the upper stage of the Saturn IB, it's somewhat different in details... And of course the interstage is markedly different.

Here's some pics demonstrating the differences...



Now I have to incorporate it all into a detail location wrap...
Later! OL JR

 

[luke strawwalker]

Got the detail location wraps done for the Saturn I-F (Saturn IB type) S-IVB stage...

And one for the interstage details including the ullage rockets...

Later! OL JR

 

[luke strawwalker]

Ok... got the Saturn I-F S-IVB greebles done...

Here's the pics...

Later! OL JR

 

[luke strawwalker]

Well, been playing with the Rocksim designs of these things... Still mulling over motor choices and stuff. Here's the Rocksim's of both the Saturn V and Saturn IF... the I-F uses Saturn V fins on the fairings, and Saturn I Block II fins between the fairings. Not sure if that's how I'll do it or not, though. May go with clear supplementary fins that plug into a pair of extra BT-20's installed in the motor mount, or something similar. I'm also still debating whether I want to go cluster or not. I may go with a single motor in both rockets.

Playing with the Saturn V, to use scale fins with a 5 motor cluster requires pretty massive amount of noseweight. To get the noseweight down requires the fins be VERY oversize, ruining the entire scale appearance of the rocket. Of course clustering also increases the risks of something going wrong, as well, for a couple seconds of "looks cool" with the five flames coming out the back, but it also increases the costs per flight as well. Eliminating the heavy cluster from the back greatly simplifies everything, allowing most of the noseweight to be ditched and allowing use of a single 24 mm motor in the center, with better looking faux F-1's surrounding it. It also allows the fins to be much smaller at the same time and still maintain stability margins. I could go with supplementary fins, either add-on clear plastic fins installed in 'dummy tubes" between the motors in the motor mount, sorta like clear flame fins or clear add-on fins similar to those balsa fins used on the Estes Mercury Atlas or the Estes Space Shuttle. One could even use clear 'slip on' fins like the Centuri? Saturn V did... but I'm still not sure...

I'm thinking about keeping it pretty close to scale and making it more neat for display while still being good to fly. This would mean keeping the fins smaller, and going with a simpler single-motor mount on both rockets, with installable twin faux F-1's on the Saturn I-F for display. That would greatly simplify prep and flying as well.

Still thinking-- Open to suggestions.

Later! OL JR

View attachment BT-80 Saturn V 152 scale.rkt

View attachment BT-60 Saturn I-F.rkt

 

[luke strawwalker]

Decals... anybody got a source of 1/152 scale Saturn V and IB decals?? I'll need them both-- the Saturn V obviously and the Saturn IB decals for the Saturn I-F...

later! OL JR